The subject matter disclosed herein relates to magnetic resonance imaging systems and, more particularly, to gradient coil driver configurations in a magnetic resonance imaging system.
The use of medical imaging technologies has become commonplace in the medical community. Such imaging technologies typically allow the acquisition of images which depict the internal structures (internal tissues and organs, bones, and so forth) and/or biochemical functions of a patient without the use of invasive procedures. That is, medical imaging technologies typically allow the internal structures and/or functions of a patient to be observed without surgery or other invasive procedures.
One such medical imaging technology is known as magnetic resonance imaging (MRI). MRI systems typically employ magnetic fields and pulses of radio frequency (RF) energy to generate images based on the gyromagnetic properties of tissues and structures within the body. For example, MRI systems may employ a primary magnetic field to generally orient susceptible molecules (such as hydrogen nuclei in water molecules) within the field and a RF pulse to disrupt this orientation. The reorientation of molecules within the primary magnetic field after this disruption may generate signals that may be detected and used to generate images of the internal structures and/or functions within the patient. Time-varying magnetic gradient fields may also be applied to the subject so that the generated signals may be localized with respect to x-, y-, and z-axes, allowing an image to be generated.
The time-varying magnetic gradient fields may be produced by gradient coils in the MRI system which are driven by pulsed sequences of current having a large dynamic range. The pulsed sequences are typically delivered to the gradient coils by gradient drivers in the MRI system. A gradient driver generally includes an array of semiconductors connected in series and/or parallel which may be stacked to drive a higher amplitude pulse sequence. However, typical configurations of gradient drivers may result in thermal instability and/or electrical losses which decreases the efficiency and/or complicates the design of the MRI system.